Usage patterns
〈人〉の一団a group/body of (people)
A group of tourists had gathered in front of the station.
一団となるto form into a single group
They formed a single group and advanced along the mountain trail.
一団を成すto form a cohesive body/group
The soldiers marched in a single formation.
一団で〈動詞〉to do something as a group
Moving around as a group can be dangerous.
